The belief that investors cannot beat the market index is often a dishonest stance held by those unwilling or unable to put in the work required to find an edge.

“I'm totally fine with index investors, but to say that there aren't investors out there that can beat the index just seems dishonest to me.”

Cliff Asness claims that markets are prone to bouts of extreme irrationality, suggesting that some markets have become less efficient over time.

“I wrote a piece called the less efficient market hypothesis about markets getting less efficient. That may be true, but I think it's more accurate to say they're what my evidence is they're prone to some extreme bouts of craziness on occasion.”